1. Field of the Invention
The invention relates to noise cancellation, and more particularly to noise cancellation in Internet communication devices.
2. Description of the Related Art
Because the cost of traditional circuit-switched telephony is great, Internet phones are frequently used to make domestic long distance and international calls. Consequently, Internet communication devices, such as VoIP devices and Instant Messengers, have become popular. For Instant Messengers such as Skype, MSN Messenger, Yahoo Messenger, Google Talker, and AOL Messenger are examples of software applications for Internet communication. Increased use of Internet communication devices demands increased audio quality of Internet communication devices. One of the greatest obstacles to audio quality of Internet communication devices is noise.
Noise from computer fans, typing, and mouse movement is often received by the microphone of an Internet communication device connected to the computer. Internet communication devices comprising noise suppression modules are typically capable of canceling a majority of the stationary noise with certain level in order not to affect too much on voice quality. In such case, quite some residual noise will be remained, even after noise suppression. In addition, normal noise suppression modules, however, cannot eliminate non-stationary noise.
Because the noise of each party is independent, when multiple parties are VoIP conferencing, the total level of noise is the sum of the noise of each party. Automatic gain control modules connected to Internet communication devices may further amplify and increase noise. Thus, a method for handling noise, particularly on non-stationary noise of Internet communication devices to improve audio quality Internet communication devices is desirable.